Vehicle transmission



Nov. 22, `1938. R. s] SANFORD ET AL 2,137,249

' VEHICLE TRANSMISSION original Filed Feb. e, 19,32 5 sheets-sheet 1 AT T NEY NQW- 22,v 1938. R. s. SANFORD ET AL. I 2,137,249

VEHICLE TRANSMISSION original Filed Feb'. e, 1932 5 sheets-,sheet 2 INVENToR.

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ATTOR EY Nov. 22, 1938. R. s. sANlFoRD Eli- Al. 2,137,249

VEHICLE YTRANSMIISSION original Filed Feb. e, 1932 5 sheets-sheet 3 Z z f "ff/6.@

INVENToR. Roy J. 4N/'01m ATTO NEY bv. 22, 1938. R. s. sANr--QIRD l-:r A1. 2,137,249

VEHICLE TRANSMISSION Original Filed Feb. 6, 1932 5 Sheets-Sheet 4 ATT NEY 'l Nv.22,193s. Rs. ANFORD ETAL 2,131,249

VEHI'ICLE TRANSMISSION original Filed Feb. e, 1932 5 sheets-sheet 5 mom Y mg M WN T AW A Gv. WMO.

Emy# MB M Patented Nov. 22, 193s VEHICLE raAsmssroN Roy S. Sanford, New York, N. Y., and Montgomery W.McConkey, South Bend, Ind., assignors to Bendix Aviation Corporation, SouthABend,

Ind., a corporation oi Delaware original application February s, l1932', serial No.

Divided and this application August 14, 1935, Serial No. 36,110 Y 1 Claim. (Cl. Z4-389.5)

This invention, which is a division of application No. 591,427, led February 6, 1932, relates to vehicles, such as automobiles, and is illustrated as embodied in the chassis of a passenger car, the particular chassis shown having individually sprung wheels and novel power transmitting mechanism between the engine and the drive i" wheels. v

An important object of the invention is to increase the eiciency and eiectivenss of the power transmitting mechanism, and to this end the same is made up as a unit, preferablysupported on the chassis frame, said unit including both speed-change and differential gearing, and thus constituting the equivalent of the conventional automotive transmission and differential units. A conventional clutch is also incorporated in the power transmission, both the clutch and aforementioned gearing being preferably power operated by driver controlled pressure differential operated vacuum motors. The several coupling elements of the power transmission as a whole, and their vacuum operation, are claimed in the aforementioned parent application and also in divisional applications No. 749,358, led October 22, 1934, and No. 752,240, leci November 9, 1934, the instant application being limited to the construction of the combined transmission and differential unit compactly mounted at the rear of the vehicle and, by virtue of 'the individual springing of each wheel, constituting a part of the sprung weight of the vehicle. t,

A feature of the invention, therefore, lies in the provision of such a power transmission unit, the

particular novelty of which lies in the combination of a forward and reverse gear unit, a socalled two-speed rear axle unit drivably coupled therewith, and a locking differential mechanism directly coupled with saidtwo-speed unit.

Other features of the invention, including types of vacuum power units for operating the twospeed rear axle unit, and other novel and desirable structures and features will be apparent from the following description of the illustrated embodiments shown inthe accompanying drawings, in which: y

Figure lis a diagrammatic assembly, view, mostly in plan but partly in vertical section through the oorboard and the instrument board to show some of the controls, of an automobile chassis embodying our invention;

Figure 2 is a horizontal section through the novel transmission-diierential unit shown in plan in Figure 1;

Figure3 is a horizontal section through the of the gear shift power unit;

Figure`7 is a section, substantially horizontal, through the clutch control power unit shown in top plan in 'Figure 13 `high-second gear shift vacuum unit, this unit -being shown in plan in Figure 1 andbeing located Figure 8 is a vertical section through the iioorboard showing a part of the fioorboarddepressible to throw out the clutch;

Figure 9 is a diagram showing the control of a power unit such as the one shown in Figure 6;

and

Figures 10 and 11l are respectively a fron-t elel vationand a vertical section, showing on a larger scale than Figurei? the control for the low-re` verse gear shift.

, The vehicle selected for illustration is an auto- .mobile chassis including an internal-combustion engine i0 having the usual intake manifold 2 and carburetor it, with the vpassage from the carburetor to the manifold controlled by the usual throttle valve having an operating arm i6.

as a lengthwise-movable rod I8, with an accelerator pedal or the like 20, and is ordinarily also independently operable through a second lost motion connection 22, for example by the usual hand throttle lever on the steering column. The accelerator pedal 2li or its equivalent is pivotally mounted on the floorboard 24, for manipulation by the toe'of-the drivers right foot. The rod I8 has a lost motion connection with the throtttle arm i6, so that it may have a short additional motion (for manipulating the clutch control valve described below) after the throttle is closed.

The engine is arranged to drive the vehicle by. driving road wheels 26 through axle shafts 28. While not necessarily so limited, the invention is especially applicable to an arrangement in which there is no axle carrying the wheels 26, instead of whichv the' wheels are individually sprung with suitable universaljoints at both ends ofrboth the axieshafts28.A '1- l The present invention has mainly to do with v The throttle arm i6 is connected, by means such which the engine |8 drives the axle shafts 28 or their equivalents.

Immediately behind the engine flywheel and its housing 38 is arranged a clutch of any desired operated by a power device 38 acting on `an arm 48 secured on the clutch shaft. Spring 42 holds the manual lever 44 in the normal position shown.

The cylinder 46 isconnected, through a fitting 48, with the intake manifold |2 by means of a conduit 58 controlled by'a valve 52 operatively connected to the crossbar 54 so that the piston 56 is automatically sucked rearwardly to disengage the clutch whenever the accelerator pedal 28 is fully or completely released. The valve 52 may be substantially as more fully described and as claimed in application No. 568,882, filed October 10, 1931, by Victor W. Kliesrath, and does not in itself form any part of the invention of the present application, and will therefore not be further described. It will be seen that the clutch is automatically disengaged whenever the accelerator pedal is released, and is rcengaged by depressing the accelerator pedal, the speed of reengagernent being controlled according to the engine speed.

The propeller shaft 34 drives the'rear axle shafts 28 through a novel unit, preferably supported on the chassis frame and shown in top plan in Figure 1 and in horizontal section in Figure 2, and which in the particular embodiment shown in these figures includes the following principal parts: (1)y a low-speed, direct-drive, reverse, change-speed gearing with a novel vacuum power operator, (2) a high-second gear shift independent of (1) and also provided with a vacuum power operator, (3) a differential or its equivalent, being shown as one form of what ls usually called a locking differential, (4) a free-wheel drive to each shaft 28, (5) a lockout, preferably power-operated, for the free-wheel drives, and (6) a pair of hydraulic or other brakes acting on' the wheels 2S through the axle shafts 28. A'The above parts are all carried by,

kand are mostly housed within, a housing or gearbox 58 formed in suitable sections bolted .together.

The propeller shaft 34 (which may if desiredv have universal joints 58 at its forward and rear ends) drives a short shaft 62journaled in a bearing 64 carried by the gear-box 58, and formed at its rear end (inside the gear-box) as a small pinion meshing with and .driving a large gear 68 forming part of a three-gear cluster rotatably mounted on a fixed countershaft 68. rI he gear cluster also includes a medium sized gear 18 and a small gear '|2, the last-named gear meshing with a reverse idler gear 14 (carried by a removable cap above or below the plane of Figure 2. and therefore indicated in dotted lines).

piloted in the rear ena of shaft es, in the.

roller bearing 16, is the ,forward end of a driven shaft 18 splined or keyed at its rear end. to an aligned pinion shaft 88 journaled in bearings 82 and 84 carried by the gear-box 58. Splined on the driven shaft '|8 is a movable driven gear 86 slidable, by a suitable shifter fork 88 from the neutral position shown in Figure 2, rearwardly to mesh with gear 18 or reverse gear 14, or forwardly to bring clutch portions on its forward face Y 2,137,24 the power transmitting mechanism through into interengagement with corresponding clutch portions on the rear face of the pinion and shaft 62 to give direct drive (this last being the normal position of gear 88).

The shifter fork 88 or its equi-valent is carried by means such as a lengthwise-slidable shifter rod 90 having a series of notches interlockingV with a spring-pressed ball 92 to give the following positions, in order from the lower (rear) end of the rod: (1) direct drive, (2) neutral, (3)1ow gear (in mesh with gear 18), (4) neutral, and (5) reverse (in mesh with gear 14).

The shifter rod 98 is shown rigidly secured, by

a crossbar or the like 94, to a piston rod 96 carried by a double-acting piston 98 in a power cylinder |88 mounted on the gear-box 58. The piston rod 96 is hollow, and contains a slide valve |82 controlling a passage |84 opening through the piston 98 into the space below (behind) the piston, and a passage |86 opening above (ahead of) the piston. The upper end of the hollow piston rod communicates with the atmosphere through openings in a plug |88 threadedy into the end of the piston rod, and the lower end of the hollow piston rod communicates with the atmosphere through a passage H8 which opens outside the power cylinder in all positions of the piston. A flexible vacuum connection H2 opens inside the hollow piston rod through a passage H4 opening through an internal collar H6 substantially midway of the piston rod, and which passage is controlled by the slide valve |82.

The valve |82 is of the follow-up type, and includes three disconnected parts; viz., upper and lower valve slides, each having an annular external groove and passages therefrom leading out through the end of the slide away from the collar H6, and a central operating button with rounded ends fitting into seats inthe adjacent faces of the valve slides, and which is of a size to pass easily through the collar H6, and which is carried by and secured to the end of .a relatively stiff Bowden wire H8 passing through plug |88.

In the operation of the power device just described, the valve |82 can be pre-set for any gear position desired, before suction is applied through conduit H2. If the Wire H8 and button on. its end are pushed downwardly (i. e. rearwardly), the lower slide valve will be pushed down to a correspondingposition. This connects theI vacuum conduit H2 through passage 38 with the space below (behind) thepiston 98, leaving the space above (in front of) the piston connected to the atmosphere. .Or if the wire is pulled upwardly (forwardly) instead, the upper valve slide is pulled in a corresponding direction, connecting the vacuum conduitk I I2 through passage |86 with`the space above (in front of) the piston 98, leaving the space below (behind) the piston connected to the atmosphere.

When now the vacuum is applied through conduit H2, the piston 98 follows the valve until the latter regains the position of parts shown in Figure 2, thereby shifting the gears to the position for which the valve 82 was pre-set.

'Ihe Bowden wire I I8 is shown passing through and operates to admit atmosphere to the cylinder |34 through the rearward portion of conduit |36, when the selector handle |26 is moved into reverse position, thus providing positive drive in reverse speed.

'Ihe conduit ||2, as shown in Figure l, is connected to the clutch control vacuum conduit 50, so that the selected shift of the gears isl made by releasing the accelerator pedal, which-at the same time throws out the clutch. The gear shift and the clutch control are thereforefinterlocked, and it is impossible to shift the gears accidentally when the clutch is` engaged.

In the arrangement of Figures 6, 9, 10 and 11, an arrangement is shown for operating the gear shift directly from the handle |26 without preselection and, if desired, without an interlock with the clutch control, but with provision for manual shifting if the power fails.

In this arrangement, the handle |26 is connected througha linkage |38 with the front portion |40 of a two-part piston rod. Portion |40 telescopes into an outer portion |42 to which the crossbar 94-and therefore the shifter rod 90.are connected.

A vacuum connection |44, corresponding to connection ||2, and which is connected to conduit 50 if an interlock with the clutch control is desired and directly to the manifold |2 if no interlock is desired, is secured to piston rod portion |40 in communication witha vacuum passage |46 opening outwardly through a collar |48 near the lower (rear) @hd of the piston rod.

An air passage |50 runs from a groove |52 in the piston rod and opens through its lower (rear) end. Air passages |54 are provided between the telescoping piston rod. sections |40 and |42, for example by making the latter a loose vfit about the former, and an opening |56 provides communication between these air passages and groove |52.

The outer piston rod section |42 is securedA at its lower (rear) end to a valve chamber |58 carrying ra double-acting power piston |60 corresponding to piston 98. The valve chamber is formed with four conical seats for valves |62, |64, |66, and |68 sleeved on the inner piston rod section |40, with a valve spring |10 compressed between valves |62 and |64 and a valve spring |12 compressed between valves |66 and |68. The collar |48 is arranged between the valves |64 and |66 and has a short lost motion vbefore engaging piston. A cup-shaped cap |18 forms a chamber over the lower end of the valve chamber |58.

In operation, with the parts as shown, thevacuum connection is sealed on* by theA valves .|64

and |66, which are held against their seats by opening valve |66, thereby opening communication between the vacuum passage |46 and thel space above (ahead of) the piston. The piston then follows up until the positions shown in Figure 6 are regained. The reverse action takes place if connections |38 are manipulated to push piston rod |40 downward (rearward). In case of failure of the power, after a short lost motion, the above-described connections shift the gears manually.

In Figure 4 is shown a modification of the power operator of Figures 1 and 2. As the operation and arrangement of the parts are the same as in Figures l and 2, they are designated by the same reference characters, with primes added where the lstructure is slightly different. The principal difference is that the connections are all made at the end of the piston rod, instead of about the center of it, thus necessitating lengthening some of the passages but 'shortening the assembly somewhat.

, Returning now to Figure 2', the pinion shaft 80 has rotatably sleeved thereon a pair of bevel pinions and |82, of different sizes, meshing respectively with a pair of different sized bevel ring gears |84 and |86. Splined on the pinion shaft 80 are a pair of dog clutches |88and |90, rigidly connected to be moved in unison by shifter forks |92 and |94, which are rigidly connected for operation by the same vertical lever |96. Shifting this assembly downwardly (rearwardly) interlocks clutch with pinion |82 and gives one speed; shifting it upwardly (forwardly) interlocks clutch |88 with pinion |80 and gives a different speed. i

-The vertical lever |96v which operates the abovedescribedgear shifting means has its' upper end connected to a piston rod |98 operated by a rdouble-acting piston 200 in a cylinder 2 02 mounted on the top of the gear-box 58, The piston rod |98 is formed with a vacuum passage 204 communicating with a flexible vacuum conduit 206, and with an air passage 208 having an air intake 2|0 to which a suitable extension, conduit, or air filter may belsecured, if desired.

The piston 200 is mounted on a slide valve member 2 I2 sleeved on the piston rod |98 between two abutments shown asprovided by snap rings 2|4 and 2|6 seated in grooves in the piston rod. The slide valve 2|2 is formed with ports registrable with openings through the sides of piston rod |98. The ends ofthe passages 204 and 208 are closed by plugs 2|8. Springs 220 and 222, clipped to the opposite ends of the cylinder 202, engagethepiston 200 and slidevalve 2|2 near the opposite ends ofits stroke. lThis power operator is more fully described and is claimed per se in application No. 580,446, filed December 11, 1931, by Roy S. Sanford. and Robert P. Breese.

The vacuum line 206 is connected to a T-tting 224 in the clutch control line 50 (to interlock this gear shift also with the clutch control) through a valve 226 shown in detail in Figure 5. This valve includes a valve cylinder 228 bolted to thel lower faceof the' floorboard 24 over an opening therein,'and containing a valve piston 230 urged upward by a fairly stiff lspring 232, and having a guide plunger 234 extending through the floorboa-rd and engaged by a heel rest or pedal 236 pivotally mounted on the floorboard just below the accelerator pedal 20, in such a position that when the toe of the drivers right foot'is on the accelerator pedal his heel is on the rest 236.

It will be seen that when the driver lifts the toe of his right foot, thereby throwing out the clutch, he may go on and depress his heel, therebyadmitting vacuum to the power device of Figure 3 and shifting from whichever pinion-and-bevelgear he has been using to the other one and thereby in effect changing gears, or, more accurately, changing speeds, since there is direct drive in both of these speeds.

The above-described power unit piston rod is shown in Figure 3 at the upper and foremost end of its stroke, with pinion |82 driving ring gear |86. If the valve 226 is manipulated as described above (and with the clutch control valve 52 also opened if the devices are interlocked with each other as shown in Figure 1),` vacuum enters through conduit 206, passage 204, and the registering ports in the piston rod and the slide valve tial.

central shaft 280 journaled in bearings 242 in cesses in its outer face.

2|2, behind the piston, while the atmosphere communicates with the space ahead of the piston through passage 208 and the registering ports inl the piston rod and slide valve aheadof the piston. The piston thereupon moves toward' the other extreme of its movement, engaging near the end of its stroke thespring 220, and shifting the clutch |90 out of engagement with pinion |82 and the clutch |88 into engagement with pinion |80, thereby changing speeds.

Now, when the heel is raised and the suction is cut off from conduit 206, air enters through a port 238 (Figure 5) into the space behind piston 200. With the air pressures now balanced on opposite sides of piston 200, spring 220 shifts the slide valve 2|2 against the abutment 2|4, ready for the next cycle of operations.

The two ring gears |84 and 86 are bolted or otherwise secured together, and are shownby way of illustration as driving the axle shafts 28 through what is known as a locking differen- Gear |86 is secured to, or integral with, a

the gear-box 58. On one end of shaft 240 is keyed or splined a clutch member 244 having external splines and having clutchsockets or re- Thei'e is a similar clutch member 246 keyed to or formed integrally of the hub part of ring gear |86 opposite the shaft 240.

The clutch members 244 and 246 are encircled by and splined to the external race members 248 of apair of overrunning roller clutches, the wedge rollers of which are indicated at 250. The inner races 252 of these roller clutches are splined to short drive shafts 254 piloted in opposite ends of shaft240 and journaled in bearings 256 car- `ried by the gear-box 58, andconnected to the axle shafts 28 through suitable universal joints 258 (not shown in detail). There are also, of course, universal joints (not shown) at the outer ends of the axle shafts 28 and through which the` axle shafts drive the wheels 26.

It will be seen that, with the parts in the positions just described, the roller clutches 248, 250, 252 act as free-wheel units through,` which the ring gear |86 (and therefore the engine 0) can drive the wheels, although the wheels cannot drive the engine. In rounding a corner, or when from any other reason the one wheel turns faster than the other, all the power goes to the slower wheel and the faster wheel overruns or freewheels. On a down grade or when motor is not driving car, both wheels can overrun .or freeengagement with the clutch recesses on the outer l faces of clutch members 244 and 246. 'I'he shift members 260 and 262 are connected to opposite ends of a double-ended piston rod 266,

which passes through both ends of a double-ended form which connects it directly to the intakemanifold |2.

While a separate control may be provided for this valve, if desired, it is shown connected to the hand throttle control rod .22 which, by reason of the lost motion provided, acts successively first to close the valve 214, then to prevent actuation of the clutch control valve 52 by preventing complete release movement of the accelerator pedal,

and nally gradually to open the engine throttle valve.

It will be noted that if -anything goes wrong with the vacuum connections the free-wheel lock- 'out described above becomes automatically operative.

Another feature of the invention relates to locating the brakes on the above-described unit, where they form part of the sprung weight, preferably between the free-wheel units 248, 250, 252 and the universal joints 258,. As shown, the brake drums 216 are secured to and carried by the shafts 28 just outside the gear-box 58. Suitable internal brakes 218, shown actuated by hydraulic cylinders 280 but which may be of any desired character,

`are carried by backing plates 282 secured to the opposite sides of the gear-box 58.

In Figure 2, a speedometer drive 284 is show'n driven from one of the shafts 254 by suitable gear-and-shaft connections.

While various' particular constructions have been described herein in detail, it is not our intention to limit the scope of the invention to those particular constructions, or` otherwise than by the terms of the appended claim.

We claim: Power transmission mechanism for an automotive vehicle provided with two lrear wheels, and

driving shafts operably connected therewith, means for driving said shafts comprising a oneway clutch unit slidably and drivably connected to each of said driving shafts, a ring gear adapted to be drivably connected to said clutch units, and means for coupling said clutch units with said ring gear. n

ROY S. SANFORD, lMON'IGOMEl-tY W. MCCONKEY. 

